Canada ultimately supplied four divisions - the Canadian Corps - to serve on the Western Front, originating with the Canadian Expeditionary Force (CEF). The CEF was formed in 1914; the Canadian Corps in September 1915.

The Canadians' first significant battle was the Second Battle of Ypres, on April 22, 1915, the first successful use of poison gas by the Germans. (It was used against the Russians in the Battle of Bolimov, a diversionary attack before the Second Battle of the Masurian Lakes, but in cold weather that helped render it ineffective.)

The Corps fought in the Battle of the Somme, and is memorialized at Courcellette: 'The Canadian Corps bore a valiant part in forcing back the Germans on these slopes during the battles of the Somme Sept. 3rd-Nov. 18th, 1916'.

On April 9 and 10, 1917, four Canadian divisions took Vimy Ridge, an action in the larger Battle of Arras, itself the British part of the Nivelle Offensive. The French had unsuccessfully tried to dislodge the Germans from the high ground of the Ridge in the Second and Third Battles of Artois in 1915.

The Newfoundland Battalion suffered horrendous casualties on July 1, 1916, the first day of the Battle of the Somme, losing 91% of its men in 40 minutes. Newfoundland was not yet part of Canada, and the Battalion itself not part of the Canadian Corps.